The present invention relates to a compressor having sliding members which are excellent in wear resistance, and more particularly, to a hermetic compressor and an open compressor using hydrocarbon refrigerant (which will be referred to as xe2x80x9cHC refrigerantxe2x80x9d hereinafter) and mineral oil or synthetic oil.
A freezer such as air conditioner, refrigerator and car cooler includes a refrigerating cycle. A hermetic compressor or an open compressor for circulating refrigerant is incorporated in the refrigerating cycle. The hermetic compressor includes a hermetic case in which a motor and a compression machine driving by this electric motor are accommodated. Compressor refrigerant is compressed, heated to high temperature and pressurized by this compression machine and discharged into the refrigerating cycle. Some conventional hermetic compressors use CFC12 refrigerant (which will be referred to as xe2x80x9cR12 refrigerantxe2x80x9d hereinafter) which is one kind of chlorofluorocarbon, HCFC22 refrigerant (which will be referred to as xe2x80x9cR22 refrigerantxe2x80x9d hereinafter) which is one kind of hydrochlorofluorocarbon, or naphthene or paraffin mineral oil having excellent compatibility with the R12 refrigerant or R22 refrigerant.
When the R12 refrigerant is used as compressor refrigerant, chlorine atoms included in the R12 refrigerant reacts with iron atoms of metal base material to form chlorine lubricant films. The lubricant film comprising the ferric chloride has self-lubricating properties and is excellent in wear resistance and prevents contact between metals to effectively prevent the wear. In addition, since the R12 refrigerant and conventional freezer oil are nonpolar, hygroscopicity is low. Therefore, the ferric chloride layer formed on iron-based metal base material does not cause hydrolytic degradation and exists as a stable lubricant film. However, since the R12 refrigerant is extremely stable chemically in the atmosphere and there is a high possibility that the R12 refrigerant destroys the ozone layer, the R12 refrigerant is designated as a restricted chlorofluorocarbon. Further, the R22 refrigerant is also a restricted chlorofluorocarbon although it is easily decomposed in the atmosphere and it has weak power to destroy the ozone layer, since the R22 still have effect to destroy the ozone layer, it has been decided internationally that the R22 refrigerant should not be used in the feature.
Recently, hydro-fluorocarbon refrigerant (which will be referred to as xe2x80x9cHFC refrigerantxe2x80x9d hereinafter) which does not destroy the ozone layer is developed as alternative chlorofluorocarbon as an alternative to specified chlorofluorocarbon or designated chlorofluorocarbon. Although the ozone destroy coefficient of the HFC refrigerant is zero, since it does not have chlorine atoms, there is a problem that the self-lubricating property is inferior. Further, when the hermetic compressor is operated using the HFC refrigerant as the compressor refrigerant, if the naphthene or paraffin mineral oil is used as the freezer oil, the compatibility with the HFC refrigerant is bad. Since such mineral oil is not solved into the HFC refrigerant, oil returning property is bad, lubricating and cooling effects of sliding portions of the compressor are impaired, and there is a possibility that problem such as seizing up is caused. Further, although the HFC refrigerant does not destroy the zone layer, since global-warming coefficient is thousands of times of carbon dioxide, it can be said that the HFC refrigerant is not sufficient in terms of terrestrial environment.
Thereupon, HC refrigerant and ammonia refrigerant are proposed as refrigerant which is not harmful to environment recently. The ammonia refrigerant attacks copper such as copper wire and thus, it is difficult to use it in the hermetic compressor. It is known that the HC refrigerant does not have the above-described problem of the ammonia refrigerant and has excellent characteristics as refrigerant for air conditioner. Naphthene or paraffin mineral oil is generally used as the freezer oil, but when the compatibility of combination of the HC refrigerant, the freezer oil and the sliding members is bad, the wear of the sliding members is increased. Thereupon, appropriate combination of the HC refrigerant, the freezer oil and the sliding members is necessary.
If the hermetic compressor or open compressor is driven for practical test using mineral oil, since the sliding members are worn, it is necessary to use material for the sliding members in which wear resistance is enhanced. Further, rather than naphthene or paraffin mineral oil, polyalkylene glycol (which will be referred to as xe2x80x9cPAG oilxe2x80x9d hereinafter), ester oil having ester linkage in molecular (which will simply be referred to as xe2x80x9cester oilxe2x80x9d hereinafter), or ether oil having ether linkage in molecular (which will simply be referred to as xe2x80x9cether oilxe2x80x9d hereinafter) may be used as the freezer oil in some cases, and it is necessary to provide the sliding members suitable for respective freezer oils. Thereupon, the present invention has been accomplished in view of the above circumstances, and it is an object to provide a hermetic compressor or an open compressor in which the wear resistance of sliding portions of a compressor is enhanced, stably driving for a long term period can be ensured, and HC refrigerant can be used.
To achieve the above objects, according to a first aspect of the present invention, there is provided a hermetic compressor comprising a hermetic case in which a motor and a compression machine are accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein freezer oil for lubricating sliding portions of the hermetic compressor is mineral oil or synthetic oil, and the sliding portions of the hermetic compressor comprise a sliding portion made of aluminum material and a sliding portion made of iron material.
Further, to achieve the above objects, according to a second aspect, the sliding portion made of aluminum material has a sliding surface which is subjected to phosphoric acid manganese treatment or molybdenum disulfide treatment, or which is subjected to phosphoric acid manganese treatment and then formed with surface treatment layer of molybdenum disulfide. According to a third aspect, the sliding portion made of iron material such as copper, cast iron sintered iron is subjected nitriding or sulfurizing nitriding, and a white layer and nitrogen-dispersed hardened layer are formed on a sliding surface of the sliding portion. According to a fourth aspect, the sliding portion made of iron material such as copper, cast iron sintered iron is subjected to PVD, CVD and plating to form a hardening treatment layer. Further, to achieve the above object, according to a fifth aspect, the hermetic compressor is a reciprocating compressor, a connecting rod belongs to the sliding portion made of aluminum material, a crankshaft belongs to the sliding portion made of iron material. According to a sixth aspect, the hermetic compressor is a scroll compressor, a movable lap belongs to the sliding portion made of aluminum material, a crankshaft, an Oldham ring or a stationary lap belongs to the sliding portion made of iron material.
According to the hermetic compressor of first to sixth aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. The sliding portion made of aluminum material has a sliding surface which is subjected to phosphoric acid manganese treatment or molybdenum disulfide treatment, or which is subjected to phosphoric acid manganese treatment and then formed with surface treatment layer of molybdenum disulfide. Therefore, wear resistance is extremely excellent, and when steel, cast iron or sintered iron is used as iron-based material for the other member, the iron-based material exhibits excellent wear resistance. In order to further enhance the wear resistance, the sliding portion made of iron material is subjected nitriding or sulfurizing nitriding, and a white layer and nitrogen-dispersed hardened layer are formed on a sliding surface of the sliding portion and thus, a sliding member having extremely excellent wear resistance is provided. If the other iron-based material is subjected to PVD, CVD and plating, adhesion properties and wear resistance are enhanced. In the actual hermetic compressor, in the case of the reciprocating type compressor, the connecting rod is made of aluminum alloy material, one of parts is a crankshaft made of iron-based material. In the case of a scroll type compressor, a movable lap is made of aluminum alloy, and one of parts is a crankshaft, Oldham ring or a stationary lap made of iron-based material. Such a hermetic compressor has extremely high reliability.
To achieve the above object, according to a seventh aspect, there is provided an open compressor comprising a case in which a compression machine is accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein mineral oil or synthetic oil being used as refrigerant for lubricating sliding portions of the open compressor, and the sliding portions of the hermetic compressor comprise a sliding portion made of aluminum material and a sliding portion made of iron material.
To achieve the above object, according to an eighth aspect, the sliding portion made of aluminum material has a sliding surface which is subjected to phosphoric acid manganese treatment or molybdenum disulfide treatment, or which is subjected to phosphoric acid manganese treatment and then formed with surface treatment layer of molybdenum disulfide. According to a aspect, the sliding portion made of iron material is subjected nitriding or sulfurizing nitriding, and a white layer and nitrogen dispersed hardened layer are formed on a sliding surface of the sliding portion. According to a aspect, the sliding portion made of iron material has a sliding surface on which a hardening treatment layer is formed. Further, to achieve the above object, according to an eleventh aspect, the open compressor is a scroll compressor, a movable lap belongs to the sliding portion made of aluminum material, a crankshaft or a Oldham ring belongs to the sliding portion made of iron material. According to a twelfth aspect, the open compressor is a scroll compressor, a vane belongs to the sliding portion made of aluminum material, a rotor or a cylinder belongs to the sliding portion made of iron material.
According to the open compressor of seventh to twelfth aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. The sliding portion made of aluminum material has a sliding surface which is subjected to phosphoric acid manganese treatment or molybdenum disulfide treatment, or which is subjected to phosphoric acid manganese treatment and then formed with surface treatment layer of molybdenum disulfide. Therefore, wear resistance is extremely excellent, and when steel, cast iron or sintered iron is used as iron-based material for the other member, the iron-based material exhibits excellent wear resistance. In order to further enhance the wear resistance, the sliding portion made of iron material is subjected nitriding or sulfurizing nitriding, and a white layer and nitrogen-dispersed hardened layer are formed on a sliding surface of the sliding portion and thus, a sliding member having extremely excellent wear resistance is provided. If the other iron-based material is subjected to PVD, CVD and plating, adhesion properties are further enhanced and wear resistance is also enhanced. In the actual open compressor, in the case of the scroll type compressor, a movable lap is made of aluminum alloy material, one of parts is a crankshaft, Oldham ring or a stationary lap made of iron-based material. In the case of a sliding vane type compressor, a vane is made of aluminum alloy material, a rotor or cylinder is made of iron-based material. Such an open compressor has extremely high reliability.
Further, according to a thirteenth aspect, there is provided a hermetic compressor comprising a hermetic case in which a motor and a compression machine are accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein freezer oil for lubricating sliding portions of the hermetic compressor is mineral oil or synthetic oil, and the sliding portions of the hermetic compressor are made of cast iron including graphite flake or cast iron material including eutectic graphite. To achieve the above object, according to a fourteenth aspect, the sliding portion has a sliding surface which is subjected to phosphoric acid manganese treatment or molybdenum disulfide treatment, or which is subjected to phosphoric acid manganese treatment and then formed with surface treatment layer of molybdenum disulfide. According to a fifteenth aspect, the hermetic compressor is a scroll compressor, a movable lap and a stationary lap are sliding portions made of cast iron including graphite flake or cast iron material including eutectic graphite.
According to the thirteenth to fifteenth aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. The sliding member is made of graphite flake cast iron or eutectic graphite cast iron, and the sliding portion has a sliding surface which is subjected to phosphoric acid manganese treatment or molybdenum disulfide treatment, or which is subjected to phosphoric acid manganese treatment and then formed with surface treatment layer of molybdenum disulfide. Therefore, wear resistance is excellent. In the actual scroll compressor, the movable lap and the stationary lap are sliding portions made of cast iron including graphite flake or cast iron material including eutectic graphite. Such a hermetic compressor has extremely high reliability.
To achieve the above object, according to a sixteenth aspect, there is provided a hermetic compressor comprising a hermetic case in which a motor and a compression machine are accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein freezer oil for lubricating sliding portions of the hermetic compressor is mineral oil or synthetic oil, the sliding portions of the hermetic compressor are made of cast iron material including spherical graphite having tensile strength of 50 kg/mm2 or greater, and a bearing is made of cast iron including spherical graphite having tensile strength of 20 kg/mm2 or greater or made of sintered iron having tensile strength of 20 kg/mm2 or greater. According to a seventeenth aspect, the hermetic compressor is a reciprocating compressor, a crankshaft is made of cast iron including spherical graphite having tensile strength of 50 kg/mm2 or greater, a bearing fixed to a stationary frame is made of graphite flake having tensile strength of 20 kg/mm2 or greater or made of sintered iron having tensile strength of 20 kg/mm2 or greater. According to an eighteenth aspect, the hermetic compressor is a rotary compressor, a crankshaft is made of cast iron including spherical graphite having tensile strength of 50 kg/mm2 or greater, the bearing is made of graphite flake having tensile strength of 20 kg/mm2 or greater or made of sintered iron having tensile strength of 20 kg/mm or greater. According to a nineteenth aspect, the hermetic compressor is a scroll compressor, a crankshaft is made of cast iron including spherical graphite having tensile strength of 50 kg/mm or greater, a main bearing is made of graphite flake having tensile strength of 20 kg/mm2 or greater or made of sintered iron having tensile strength of 20 kg/mm2 or greater.
According to the sixteenth to nineteenth aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. One of the sliding members is made of cast iron material including spherical graphite having tensile strength of 50 kg/mm2 or greater, and the other sliding member is made of cast iron including spherical graphite having tensile strength of 20 kg/mm2 or greater or made of sintered iron having tensile strength of 20 kg/mm2 or greater. Such a compressor is extremely excellent in wear resistance. In the actual reciprocating hermetic compressor, the one sliding member is the crankshaft and the other sliding member is the bearing fixed to the stationary frame. In the rotary compressor, the one sliding member is the crankshaft and the other sliding member is the main or auxiliary bearing. In the scroll compressor, the one sliding member is the crankshaft and the other sliding member is the main bearing. Such a hermetic compressor has extremely high reliability.
To achieve the above object, according to a twentieth aspect, there is provided an open compressor comprising a case in which a compression machine is accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein mineral oil or synthetic oil being used as refrigerant for lubricating sliding portions of the open compressor, the sliding portions of the open compressor are made of cast iron material including spherical graphite having tensile strength of 50 kg/mm2 or greater, and partner sliding portions are made of cast iron including graphite flake having tensile strength of 20 kg/mm2 or greater or made of sintered bearing material having tensile strength of 20 kg/mm2 or greater. According to a twenty-first aspect, the hermetic compressor is a reciprocating compressor, a crankshaft is made of cast iron material including spherical graphite having tensile strength of 20 kg/mm2 or greater, a bearing fixed to a stationary frame is made of graphite flake having tensile strength of 20 kg/mm2 or greater or made of sintered iron having tensile strength of 20 kg/mm2 or greater.
According to a twenty-second aspect, the hermetic compressor is a rotary compressor, a crankshaft is made of cast iron including spherical graphite having tensile strength of 50 kg/mm2 or greater, the bearing is made of cast iron material including graphite flake having tensile strength of 20 kg/mm2 or greater or made of sintered bearing material having tensile strength of 20 kg/mm2 or greater.
According to a twenty-third aspect, the hermetic compressor is a scroll compressor, a crankshaft is made of cast iron including spherical graphite having tensile strength of 50 kg/mm2 or greater, a main bearing is made of cast iron material including graphite flake having tensile strength of 20 kg/mm2 or greater or made of sintered bearing material having tensile strength of 20 kg/mm2 or greater.
According to the open compressor of the twentieth to twenty-third aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. One of the sliding members is made of cast iron material including spherical graphite having tensile strength of 50 kg/mm2 or greater, and the other sliding member is made of cast iron including spherical graphite having tensile strength of 20 kg/mm2 or greater or made of sintered iron having tensile strength of 20 kg/mm2 or greater. Such a compressor is extremely excellent in wear resistance. In the actual reciprocating hermetic compressor, the one sliding member is the crankshaft and the other sliding member is the bearing fixed to the stationary frame. In the rotary compressor, the one sliding member is the crankshaft and the other sliding member is the main or auxiliary bearing. In the scroll compressor, the one sliding member is the crankshaft and the other sliding member is the main bearing. Such a hermetic compressor has extremely high reliability.
To achieve the above object, according to a twenty-fourth aspect, there is provided a hermetic compressor comprising a hermetic case in which a motor and a compression machine are accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein freezer oil for lubricating sliding portions of the hermetic compressor is mineral oil or synthetic oil, and the sliding portions of the hermetic compressor comprise both a sliding portion made of SKH51 material and a sliding portion made of cast iron material including graphite flake having 10% or less of ferrite or made of cast iron material including eutectic graphite having 50% or less of pearlite.
According to a twenty-fifth aspect, the hermetic compressor is a rotary compressor, the compressor comprises a vane is made of SKH51 material, and a cylinder made of cast iron material including graphite flake having 10% or less of ferrite or made of cast iron material including eutectic graphite having 50% or less of pearlite.
According to the twenty-fourth and twenty-fifth aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. One of the sliding member is made of SKH51 material, and the other sliding member is made of cast iron material including graphite flake having 10% or less of ferrite or made of cast iron material including eutectic graphite having 50% or less of pearlite. In the actual case, the hermetic compressor is a rotary compressor, the one sliding member is a vane and the other sliding member is a cylinder. Such a hermetic compressor has extremely high reliability.
To achieve the above object, according to a twenty-sixth aspect, there is provide a hermetic compressor comprising a hermetic case in which a motor and a compression machine are accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein freezer oil for lubricating sliding portions of the hermetic compressor is mineral oil or synthetic oil, and the sliding portions of the hermetic compressor comprise both a sliding portion made of SKH51 material and a sliding portion made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium oxide and hardness of HRC45 or greater. According to a twenty-seventh aspect, the hermetic compressor is a rotary compressor, a vane belongs to a sliding portion made of SKH51 material, and a piston belongs to a sliding portion made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium oxide and hardness of HRC45 or greater.
According to the twenty-sixth and twenty-seventh aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. One of the sliding member is made of SKH51 material, and the other sliding member is made of made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium oxide and hardness of HRC45 or greater. In the actual case, the hermetic compressor is a rotary compressor, the one sliding member is a vane and the other sliding member is a piston. Such a hermetic compressor has extremely high reliability.
To achieve the above object, according to a twenty-eighth aspect, there is provided a hermetic compressor comprising a hermetic case in which a motor and a compression machine are accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein freezer oil for lubricating sliding portions of the hermetic compressor is mineral oil or synthetic oil, and bearing sliding portions constituting the sliding portions of the hermetic compressor are made of sintered iron material having sintering density of 6.5 g.cm3.
According to a twenty-ninth aspect, the bearing sliding portions are made of bearing sintered iron material having metal including 1 to 3 weight % of copper, 0.5 to 0.9 weight % of carbon and a balance mainly comprising iron.
According to a thirtieth aspect, the bearing sliding portions are made of sintered iron material sealed with self-lubricating material such as ethylene tetrafluoride, molybdenum sulfide, copper, tin and bronze.
According to the twenty-eighth to thirtieth aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. The sliding member is made of sintered iron material having sintering density of 6.5 g.cm3, or made of bearing sintered iron material having metal including 1 to 3 weight % of copper, and 0.5 to 0.9 weight % of carbon, or made of of sintered iron material sealed with self-lubricating material such as ethylene tetrafluoride, molybdenum sulfide, copper, tin and bronze. Such a hermetic compressor has extremely high reliability.
To achieve the above object, according to a thirty-first aspect, there is provided a hermetic compressor comprising a hermetic case in which a motor and a compression machine are accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein freezer oil for lubricating sliding portions of the hermetic compressor is mineral oil or synthetic oil, and the sliding portions of the hermetic compressor comprise both a sliding portion having a sliding surface which is nitrided and formed with a white layer, and a sliding portion made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium.
According to a thirty-second aspect, the hermetic compressor is a rotary compressor, a vane belongs to a sliding portion having a sliding surface which is nitrided and formed with a white layer, and a roller belongs to a sliding portion made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium, and at least a tip end of the vane has a nitrided white layer.
According to a thirty-third aspect, the vane is made of SKH material or melted SUS material, a surface of the vane is nitrided, and the surface is formed with the white layer of 3 xcexcm or greater.
According to the thirty-first to thirty-third aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. One of the sliding members is nitrided and formed at its surface with a white layer, and the other sliding members is made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium and hardness of HRC45 or greater. In actual case, the hermetic compressor is a rotary compressor, and one of the sliding members is a vane and the other sliding member is a piston. Such a hermetic compressor has extremely high reliability.
To achieve the above object, according to a thirty-fourth aspect, there is provided a rotary hermetic compressor comprising a hermetic case in which a motor and a compression machine are accommodated, and hydrocarbon refrigerant being used as refrigerant to be compressed by the compression machine, wherein freezer oil for lubricating sliding portions of the hermetic compressor is mineral oil or synthetic oil, and the sliding portions of the hermetic compressor has both a sliding portion made of iron-based sintered material including chromium carbide, or sintered SKH material or SUS material, and a sliding portion made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium and hardness of HRC45 or greater.
According to a thirty-fifth aspect, the hermetic compressor is a rotary compressor, a vane belongs to the sliding portion made of iron-based sintered material including chromium carbide, or sintered SKH material or SUS material, a roller belongs to the sliding portion made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium and hardness of HRC45 or greater, and the material of the vane includes 60 weight % or greater of SKH51 sintered material.
According to the thirty-fourth and thirty-fifth aspects, in HC refrigerant, mineral oil or synthetic oil such as PAG oil, ester oil and ether oil is used as the freezer oil. One of the sliding members is made of sintered material including chromium carbide, or sintered SKH material or SUS material, and the other sliding member is made of sintered and tempered nickel-chromium-molybdenum cast iron material including 0.4 to 1.0 weight % of chromium and hardness of HRC45 or greater. In actual case, the hermetic compressor is a rotary compressor, and one of the sliding members is a vane and the other sliding member is a piston. Such a hermetic compressor has extremely high reliability.